Cai Na, Wang Xueping, Zhu Haixia, Hu Yan, Zhang Xiying, Wang Lingqing
Key Laboratory of Green and High-end Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, 810008, China; Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes, Xining, 810008, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Ministry of Education, Chang'an University, Xi'an, 710054, China; School of Water and Environment, Chang'an University, Xi'an, 710054, China.
Environ Res. 2024 Jun 15;251(Pt 1):118626. doi: 10.1016/j.envres.2024.118626. Epub 2024 Mar 11.
The research was carried out to examine the pollution characteristics, ecological risk, and origins of seven heavy metals (Hg, As, Pb, Cu, Cd, Zn, and Ni) in 51 sediment samples gathered from 8 rivers located on the Qinghai-Tibet Plateau (QTP) in China. The contents of Hg and Cd were 5.0 and 1.1 times higher than their background values, respectively. The mean levels of other measured heavy metals were below those found naturally in the local soil. The enrichment factor showed that the study area exhibited significantly enriched Hg with 70.6% sampling sites. The Cd contents at 19.6% of sampling sites were moderately enriched. The other sampling sites were at a less enriched level. The sediments of all the rivers had a medium level of potential ecological risk. Hg was the major ecological risk factor in all sampling sites, followed by Cd. The findings from the positive matrix factorization (PMF) analysis shown agricultural activities, industrial activities, traffic emissions, and parent material were the major sources. The upper, middle, and low reaches of the Quanji river had different Hg isotope compositions, while sediments near the middle reaches were similar to the δHg of the industrial source. At the upstream sampling sites, the Hg isotope content was very close to the background level. The results of this research can establish a strong scientific sound to improve the safety of the natural circumstances of rivers on the QTP.
本研究旨在调查从中国青藏高原8条河流采集的51个沉积物样本中7种重金属（汞、砷、铅、铜、镉、锌和镍）的污染特征、生态风险及来源。汞和镉的含量分别比其背景值高5.0倍和1.1倍。其他实测重金属的平均含量低于当地土壤中的天然含量。富集因子表明，研究区域70.6%的采样点汞显著富集，19.6%的采样点镉含量中等富集，其他采样点富集程度较低。所有河流的沉积物潜在生态风险均为中等水平。汞是所有采样点的主要生态风险因子，其次是镉。正定矩阵因子分解（PMF）分析结果表明，农业活动、工业活动、交通排放和母质是主要来源。泉吉河的上游、中游和下游汞同位素组成不同，中游附近沉积物的δHg与工业源相似。在上游采样点，汞同位素含量非常接近背景水平。本研究结果可为提高青藏高原河流自然环境安全性提供有力的科学依据。
